Food products to provide supplemental amounts of nutritional components to a consumer have become increasingly popular in recent years. Both solid food items and beverages are available that provide desired nutritional components to individuals who seek nutritional supplements as a result of diet or activity level. For example, various beverages and snacks have been suggested to address the nutritional needs of children or athletes. Nutritional bars can deliver relatively high levels of nutritional ingredients in a single serving size. Beverages also can be used to quickly deliver the desired nutritional components.
Protein is one nutritional component that often is sought in dietary supplements. Among the numerous sources of protein, whey proteins have a high nutritive value, due in part at least to the compositional profile of the proteins that includes a balanced array of amino acids. As a result, whey proteins are recognized as a premier protein source, particularly for individuals who are health-conscious and have specific dietary needs, such as athletes and body builders. Generally, it is desired to provide as much protein as possible from whey proteins.
Various problems associated with incorporation of proteins, particularly whey proteins, have prevented their successful use as the sole source of protein in food products, such as nutritional supplement bars and beverages. For example, although a protein bar that includes 100% of protein from whey protein may initially have acceptable flavor and texture characteristics, these characteristics will rapidly decline, within a matter of weeks even, so that the bar is no longer appealing to the consumer. In particular, an overall hardening of the bar results in decreased shelf life and a generally unacceptable food product. Such a protein bar is no longer suitable for commercial sale and consumption. These problems also have prevented preparation of food products having higher levels of whey proteins, such as greater than about 25 weight percent protein. To overcome these problems, food products such as protein bars typically include a blend of protein sources, including but not limited to whey proteins, milk proteins, wheat proteins, calcium caseinate, skim milk, soy proteins and others to achieve a soft food product having a longer shelf life.
Nutritional liquid compositions or beverages, such as sports nutrition beverages, also suffer from problems as the protein fraction from whey protein is increased. Drinks are available that contain only whey proteins, however, such drinks are acidic (pH less than 4.5) in order to provide a stable food product. As a result of the high acidity, their flavor may be unappealing to consumers. Additionally, the beverages typically are clear liquids so that appearance can be a concern.
Efforts to provide a neutral pH beverage, and thus limit the acidic “bite” associated with nutrition beverages, while maintaining whey protein as the only protein source have been difficult at best. As the pH of a whey protein beverage is increased, the ability of the beverage to withstand heat treatment decreases and the physical properties of the beverage tend to become unstable. For example, attempts to use whey protein as the sole protein source in a neutral pH beverage that delivers supplemental amounts of protein have been unsuccessful. Whey proteins become cloudy and/or precipitate when subjected to elevated temperatures, such as during pasteurization, which is typically a required processing step. Thus, other less-desirable forms of protein, including but not limited to caseinates and soy proteins, have been used in addition to, or instead of, whey proteins to deliver the desired amount of protein to the consumer while providing a stable beverage product.
There remains a need for compositions that allow incorporation of whey proteins as the primary or even sole protein source and that can be used to prepare food products of desired taste and texture. There also remains a need for food products that deliver supplemental amounts of nutritional components such as protein and that remain stable when subjected to conditions including heat and time.